Question

variations within a species are an important part of charles darwins theory of evolution. which example can be explained by individual variation?
the food source in a lake is not enough to support the bass population, but it can support the trout.
a population of brown bears has doubled in the past 10 years as its habitat size has increased.
owls and foxes compete fiercely against each other for small rodents in their habitat.
brightly colored cardinals are better able to survive and to reproduce than darker cardinals.

Explanation:

Individual variation refers to differences in traits among members of the same species, which drives natural selection. The first three options involve interactions between different species or population changes from habitat/food shifts, not within-species trait differences. The last option describes variation in feather color (a trait within cardinals) and how this difference impacts survival/reproduction, which aligns with Darwin's focus on individual variation in evolution.

Answer:

D. Brightly colored cardinals are better able to survive and to reproduce than darker cardinals.